Underground chilled water pipes

[Hasny]

I have to embed around 15 meters of chilled water supply and return lines. I will give them min two coates to epoxy paint, insulate them with rigid fiber glass pipe insulation having vapor barrier over it, and finally wrap around the whole length with denso tape. Please do share if I have missed something. *I have read somewhere that pipe should be painted with two coats of zinc chromate, does it give a better protection against moisture. Thanks

[Hasny]

Does an underground chilled water pipe entering a building through grade beam or a wall require any kind of pipe sleeve. If so, what should be the material of the sleeve if the pipe entering is carbon steel, Sch 40. Thanks

[beenthere]

Merged your threads on this, and moved them to Tech to Tech.

[welling service]

I would definitely install a sleeve at the building entrance and as far as the zinc chromate is concerned it can't hurt but just make sure no moisture can get to the pipe.

[alcomech]

Have you considered using pre-insulated pipe such as Perma pipe or Ricwil.

I have made my own using standard Sch 40 PVC pipe and polyurethane foam which is available as a two part mixture and is used to insulate piping.

As for the penetration through a wall this is normally required and also requires a link seal for expansion and water seal.

[Hasny]

@Alcomech - pre insulted pipes are not in much use here. Usually it's the PVC or Carbon Steel that we use for the embedded lengths of pressure pipes.